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Help25-Hydroxyvitamin D2 and D3, Serum
Reporting Name
25-Hydroxyvitamin D2 and D3, SSynonym: Vit D Fractionated
Useful For
Diagnosis of vitamin D deficiency
Differential diagnosis of causes of rickets and osteomalacia
Monitoring vitamin D replacement therapy
Diagnosis of hypervitaminosis D
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial within 2 hours of specimen collection.
Specimen Minimum Volume
0.25 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 28 days |
| Frozen | 30 days | |
| Ambient | 7 days |
Reference Values
TOTAL 25-HYDROXYVITAMIN D2 AND D3 (25-OH-VitD)
<10 ng/mL (severe deficiency)*
10-19 ng/mL (mild to moderate deficiency)**
20-50 ng/mL (optimum levels)***
51-80 ng/mL (increased risk of hypercalciuria)****
>80 ng/mL (toxicity possible)*****
*Could be associated with osteomalacia or rickets
**Might be associated with increased risk of osteoporosis or secondary hyperparathyroidism
***Optimum levels in the healthy population
****Sustained levels >50 ng/mL 25OH-VitD along with prolonged calcium supplementation may lead to hypercalciuria and decreased kidney function
*****80 ng/mL is the lowest reported level associated with toxicity in patients without primary hyperparathyroidism who have normal kidney function. Most patients with toxicity have levels >150 ng/mL. Patients with kidney failure can have very high 25-OH-VitD levels without any signs of toxicity, as renal conversion to the active hormone 1,25-OH-VitD is impaired or absent.
These reference ranges represent clinical decision values, based on the 2011 Institute of Medicine report, that apply to males and females of all ages, rather than population-based reference values. Population reference ranges for 25-OH-VitD vary widely depending on ethnic background, age, geographic location of the studied populations, and the sampling season. Population-based ranges correlate poorly with serum 25-OH-VitD concentrations that are associated with biologically and clinically relevant vitamin D effects and are therefore of limited clinical value.
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Day(s) Performed
Monday through Friday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82306
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| 25HDN | 25-Hydroxyvitamin D2 and D3, S | 49590-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 2897 | 25-Hydroxy D2 | 49054-0 |
| 2898 | 25-Hydroxy D3 | 1989-3 |
| 83670 | 25-Hydroxy D Total | 62292-8 |
Method Description
Deuterated stable isotopes (d6-25-hydroxyvitamin D3 [25-OH-VitD3] and d3-25-hydroxyvitamin D2) are added to a 0.1-mL serum sample as internal standard. Proteins are precipitated by addition of a crash solution and separated from supernatant by centrifugation. The supernatant is injected onto a TX system for purification by an online extraction column followed by transfer to an analytical column for separation of analytes. 25-OH-VitD and D3 are analyzed by mass spectrometry using multiple reaction monitoring. 25-OH-VitD2 and D3 are quantified and reported individually and as a sum with a clinical reference range attached to the sum. C-3 epimers of 25-OH-VitD2 and D3 are chromatographically separated and not included in the results.(Dirks NF, Cavalier E, Heijboer AC. Vitamin D: marker, measurand and measurement. Endocr Connect. 2023;12(4):e220269. doi:10.1530/EC-22-0269)
Report Available
2 to 5 daysReject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Portions of this test are covered by patents held by Quest Diagnostics
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Renal Diagnostics Test Request (T830)